1. Field of the Invention
The present invention relates to a vehicle having a main frame having a plurality of members.
2. Description of the Related Art
Conventionally, in a vehicle including a main frame having a plurality of members, for example, in a vehicle having a monocoque structure, outer and inner panels that constitute the main frame of the vehicle are made of a steel sheet (a high tensile steel sheet or a super high tensile steel sheet), an iron sheet, an aluminum sheet, or the like. In order to ensure that a vehicle cabin space is safe against an instantaneous impact from a front direction or a side direction, or against an offset collision, such a monocoque structure is required to have sufficient strength and stiffness (transmission of force).
On the other hand, when the vehicle drives around a curve, driving stability that is influenced by transmission of a load is required. Accordingly, a balance is required between driving stability and collision safety that is influenced by strength against a collision such as that described above.
Furthermore, it is required to prevent noise from being generated and transmitted due to vibration and the like. Also, the vehicle having a monocoque structure includes front pillars, side roof rails, center pillars, door sills, and the like. In order to efficiently disperse a load or an impact applied to the respective members, sufficient joint stiffness is required on a junction of the respective members and a bent portion in which the direction of force transmission is changed.
For example, Japanese Unexamined Patent Application Publication (JP-A) No. 2000-108930 discloses a lower structure of a vehicle side that securely disperses and transmits a collision load from a front or side of a vehicle to other members and suppresses deformation due to the collision.
JP-A No. 2001-71948 discloses a structure that is provided on a side roof of a vehicle side with a rail reinforcing member and on a door sill with a sill strength adjusting member, respectively, and that changes the vehicle deformation mode upon the occurrence of a side collision.
On the other hand, JP-A No. 2004-123036 discloses a technique for molding at least either one of an inner panel and an outer panel out of fiber reinforced plastics in a structure for fixing a securing wire harness to a vehicle body.
However, in the above three Japanese Unexamined Patent Application Publications, the vehicle frame has insufficient strength and stiffness in view of driving stability and collision safety.
Also, in the above three Japanese Unexamined Patent Application Publications, the vehicle frame cannot prevent noise from being generated and transmitted due to vibration or the like. Furthermore, the vehicle frame does not have sufficient joint stiffness to adequately transmit a force applied to a junction among members and a bent portion of a member.